We are surrounded by many rigid items of street furniture which can be unintentionally collided with, resulting in damage not only to the rigid items of street furniture but also to the object (e.g. a vehicle) or in injury to the person who collides with the item of street furniture.
In the context of the invention the term “item of street furniture” covers, among other things, the following objects (the list is not exhaustive), all of which are either mounted on the ground or secured to a wall, namely:                Poles or supports of traffic signs;        Poles or supports of advertising boardings;        Poles or supports of parking meters;        Supports of sign boards or canopies;        Protective posts which stand or are suspended in front of an object to be protected;        Supports for conveyor belts;        Supporting posts of guard rail structures or protective brackets;        Posts for braking falling and/or rolling loads;        Lamp posts;        Poles or supports of traffic lights;        And similar objects.        
It is now known from a number of documents that such items of street furniture can be designed so that the consequences of minor collisions, contacts or gusts of wind can be limited. Indeed some items of street furniture bend completely so that the object or person which/who caused the collision is/are able to move over the item of street furniture. It is possible that such items of street furniture are energy-absorbing, but they are not impact-resistant in all cases.
However, the invention relates to an item of street furniture which on the one hand will limit this damage and/or injury in a collision/contact with both the item of street furniture and the colliding object or person in the case of minor collisions/contacts (this is the energy-absorbing part), whereupon the item of street furniture springs back into its normal position, whilst on the other hand the item of street furniture still performs a protective function from a defined degree of collision/contact, namely bringing the object or person which/who caused the collision/contact to a standstill (this is the impact-resistant part) without losing its resilient capacity.
The European patent EP-B-2 267 225 (Wolters) already describes such an item of street furniture, namely an impact-resistant and energy-absorbing protective post. In such an item of street furniture the number of parts is limited to the absolute minimum, namely three (a post, a base plate and an energy-absorbing element) and is additionally assembled by simply sliding the post, the base plate and the energy-absorbing element into one another and by simply anchoring the base plate to an existing ground surface (e.g. to the ground or to an existing floor) or to a wall. The sliding of these parts into one another is extremely simple because they are not fastened to one another, but only lie in contact with one another. In this connection it is pointed out that the terms “post” and “base plate”, in the context of the invention, must be understood that they can be composed of different parts, parts which when in use form one unit, i.e. they are firmly connected to each other so that when in use no relative movement between these parts is possible.
The, preferably, absence of parts of the item of street furniture below ground level prevents submersion or the seeping in of water and the associated corrosion. When maintaining or replacing the few parts the item of street furniture can be dismantled in situ with simple tools and parts can be replaced if necessary. The energy-absorbing element is also located above ground in the item of street furniture in an easily accessible position.
Therefore the manufacture and use of the item of street furniture are simple, whilst it can be manufactured and repaired at low cost.
It is also important for the post to be the impact-absorbing element, i.e. practically every point on the post, throughout its length, can be an active point of application for the external forces which act on the item of street furniture with full retention of the impact and absorbing properties. These external forces may be either a vehicle, a person, the wind or the like.
The post may be the only impact-absorbing element, which means that part of the item of street furniture which can be moved by an object, a person or the wind, because the base plate is kept as low as possible, thus enabling a vehicle or a person to collide under normal circumstances only against the post and not against the base plate.
The range of the energy absorption of the individual item of street furniture can easily be adapted to changing circumstances by adjusting the energy-absorbing element in situ.
The colliding action may take place in two steps, namely a spring action followed, if necessary, by a rigid action.
In this state of the art, the base plate has to be kept as low as possible, so that under normal circumstances a vehicle or a person only can collide against the post and not against that base plate. The point or place of application for the external forces on the post can either be relatively high or relatively low with respect to the ground level, what will have an influence on the elastic action of the energy-absorbing element. When that point or place of application for the external forces is located on the post relatively high above the base plate, there is created a large pivoting- or tipping torque, that acts on the post, so that the post directly executes a pivoting- or tipping movement with respect to the base plate. When, however, the same external forces act now on a very low point or place of application of the post (i.e. just above the base plate) then the pivoting- or tipping torque, which acts on the post, is much lower when compared with the torque created with a normal point or place of application. Thereby, the post, which is always pressed against the base plate by the energy-absorbing element and which is additionally under the influence of the mostly horizontal external forces just above the base plate, will not solely be directly pivoted or tipped, but will also be shifted in the same direction as that of the external forces.